Undervoltage Detection Bugfix

Fixed potential bug that could prevent sudden undervoltage detection due to a short circuit and removed makeshift NiCd battery support.

Command Line Build

Support command line build via Makefile. Among others, the following make targets are supported:

• make all: Build the Arduino firmware
• make upload: Upload to the Arduino board
• make clean: Remove all build artifacts
• make release: Create a .zip file with the firmware source code

The following environment variables need to be defined on your
host system (the actual values depend on your system configuration):
export ARDUINO_DIR=/opt/arduino
export ARDMK_DIR=/opt/arduino-mk
export MONITOR_PORT=/dev/ttyUSB0

Refactoring

Moved parts of the source code to separate Git submodules.

Further Compile Error Fix

Fixed a further capitalization error that prevented the code from compiling on a case-sensitive file system.

Compile Error Fix

Fixed a compile-error on case-sensitive file systems, caused by wrong file name capitalization within include statements.

Improved Validation and PWM Update

• If parameter validation fails, the parameter is not written to EEPROM and an error message is displayed
• Synchronize PWM updating with ADC read cycles, this ensures that a fresh ADC reading is available prior to updating the PWM frequency
• The system state is now printed within the output of the . (dot) command

Increased PWM Frequency and Easier Calibration

• Increased PWM frequency to 31.250KHz
• Improved calibration procedure: the exact reference voltage value is now passed as an argument, so there is no more need to use a precision power supply
• Harmonized CLI command names to match the ones of pi-ups
• Check the number of arguments passed to the CLI commands that require numerical input
• Set the failsafe value of R_shunt to 100mΩ

Fixed a Minor Bug and Improved Code Comments

• Removed duplicate initialization of tickTs = ts
• Updated inconsistent parameter and function descriptions

Increased Test Coverage

Test Coverage

• Depleted Li-Ion battery with BMS cutooff
• Almost full Li-Ion battery
• Full charge cycle
• Trickle charge cycle
• End-of-charge detection
• Sanity-check charge time and remaining capacity estimation
• Makeshift NiCd charging support

New features

• System trace: trace real-time charging parameters to EEPROM

Enhancements

• Fine-tune charge time and remaining capacity estimation
• Increase the speed of reaction to sudden current or voltage increase
• Remove end-of-charge detection based on current increase
• Improve voltage-based end-of-charge detection

Optimization and Test Coverage

• Reuse strings in different places to save memory
• I_safe is now a factor of I_chrg
• Test very low voltage use cases
• Test I_safe
• Test Trickle Charging